Arson is suspected in a fire which damaged a North Shore Shark Adventures tour boat and a privately owned vessel parked next to it in Haleiwa Harbor last night.

It’s the third North Shore Shark Adventures tour boat to be set ablaze this year.

Waialua firefighters arrived at 11:42 p.m. to find the cabin and deck of the 35-foot  shark tour boat in flame on a trailer in the Haleiwa Harbor trailer yard. The fire was brought under control five minutes later. Damage is estimated at $100,000.

Heat from the first fire also caused $20,000 damage to a 40-foot private boat on an adjacent trailer, Honolulu Fire Department spokesman Capt. Terry Seelig said.

State Land Board Director William Aila said the fire was an "unfortunate incident."

Aila, who was at the Haleiwa Boat Harbor this morning as state crews were surveying tsunami damage to piers, said the two boats were on trailers in the parking lot off Haleiwa Road.

He said there are no night security patrols at any state boat harbors because of budget cuts.

Aila said there have been no new leads on the previous fires, which happened to boats moored in the harbor.

A fire reported just after midnight on Jan. 24 caused an estimated $225,000 damage to the cabin and front end of the 30-foot North Shore Shark Adventures tour boat Kailolo.

The 30-foot North Shore Shark Adventures tour boat Kolohe burned in a 12:30 a.m. fire on Jan. 7. Damage was also estimated at $225,000.

Investigators determined the January fires were also deliberately set.

Seelig said the investigation has been turned over to Honolulu police. He said anyone with information is asked to call police or CrimeStoppers.

Aila said North Shore Shark Adventures planned to replace the two boats that had been damaged in January.

Joe Pavsek, owner of North Shore Shark Adventures, was on Lanai today and unavailable for comment.

Besides North Shore Shark Adventures, Hawaii Shark Encounters also offers shark tours out of Haleiwa Harbor.

The business has been controversial because of the practice of feeding sharks to attract them.

Feeding sharks is illegal in state waters within three miles of shore.

Five shark tour workers were arrested last year for feeding sharks within the three mile limit, but a state judge threw out the charges in January just before the case went to trial.

Opponents of shark feeding say the practice attracts sharks, hurts fisheries, and is disrespectful to native Hawaiians who believe sharks are amakua or ancestral gods.

But shark tour operators say they only venture into areas where sharks are already present. They say sharks have congregated in the area off the north shore since the 1960s, when crabbing boats used to throw out old bait into the ocean from their traps.

Mahina Chillingworth of Hui o Hee Nalu, a North Shore group of surfers and other community members opposed to shark feeding, said: "We’re beyond surprise or disbelief" to hear that more boats have been set ablaze on purpose. She said this is something her organization would never condone.

"The hui has never been anti-business," she added. "That’s not pono. That’s not the local way."